/Engine/Source/Runtime/Engine/Classes/Components/AudioComponent.h
Sets how much audio the sound should send to the given Audio Bus (POST Source Effects). if the Audio Bus Send doesn't already exist, it will be added to the overrides on the active sound.
void SetAudioBusSendPostEffect ( [UAudioBus](API\Runtime\Engine\Sound\UAudioBus) * AudioBus, float AudioBusSendLevel )